The first picture looks like a quarry cut to me, square like cuts and long lines make almost block like lines similar to what you would see on a bank along a highway. Interesting troth in the first two pictures, is there gravel at the bottom of it? Does water move through it naturally? The reason I ask, this could have been a _________ mine from the 1800s. Is it the same seam in third picture as in the top of second picture? Also, is the seam horizontal or does it look heaved and angled to one side? The pillar looks like it was picked at and possibly the left side too, the right side looks more natural weathering. Remember that back in the old days people would mine their own resources like lead, iron, salt peter and even exposed coal seams. They were dirt poor and did what they had to do to get by. I agree that you should get a sample of the exposed seam(s) of both areas and get an assay. Whatever it is or was, they didn't go very deep in their pursuits did they?
